Prokineticin 2 Regulates the Electrical Activity of Rat Suprachiasmatic Nuclei Neurons

Neuropeptide signaling plays roles in coordinating cellular activities and maintaining robust oscillations within the mammalian suprachiasmatic nucleus (SCN). Prokineticin2 (PK2) is a signaling molecule from the SCN and involves in the generation of circadian locomotor activity. Prokineticin receptor 2 (PKR2), a receptor for PK2, has been shown to be expressed in the SCN. However, very little is known about the cellular action of PK2 within the SCN. In the present study, we investigated the effect of PK2 on spontaneous firing and miniature inhibitory postsynaptic currents (mIPSCs) using whole cell patch-clamp recording in the SCN slices. PK2 dose-dependently increased spontaneous firing rates in most neurons from the dorsal SCN. PK2 acted postsynaptically to reduce γ-aminobutyric acid (GABA)-ergic function within the SCN, and PK2 reduced the amplitude but not frequency of mIPSCs. Furthermore, PK2 also suppressed exogenous GABA-induced currents. And the inhibitory effect of PK2 required PKC activation in the postsynaptic cells. Our data suggest that PK2 could alter cellular activities within the SCN and may influence behavioral and physiological rhythms

Transcriptome Analysis of the Hippocampal CA1 Pyramidal Cell Region after Kainic Acid-Induced Status Epilepticus in Juvenile Rats

Molecular mechanisms involved in epileptogenesis in the developing brain remain poorly understood. The gene array approach could reveal some of the factors involved by allowing the identification of a broad scale of genes altered by seizures. In this study we used microarray analysis to reveal the gene expression profile of the laser microdissected hippocampal CA1 subregion one week after kainic acid (KA)-induced status epilepticus (SE) in 21-day-old rats, which are developmentally roughly comparable to juvenile children. The gene expression analysis with the Chipster software generated a total of 1592 differently expressed genes in the CA1 subregion of KA-treated rats compared to control rats. The KEGG database revealed that the identified genes were involved in pathways such as oxidative phosporylation (26 genes changed), and long-term potentiation (LTP; 18 genes changed). Also genes involved in Ca2+ homeostasis, gliosis, inflammation, and GABAergic transmission were altered. To validate the microarray results we further examined the protein expression for a subset of selected genes, glial fibrillary protein (GFAP), apolipoprotein E (apo E), cannabinoid type 1 receptor (CB1), Purkinje cell protein 4 (PEP-19), and interleukin 8 receptor (CXCR1), with immunohistochemistry, which confirmed the transcriptome results. Our results showed that SE resulted in no obvious CA1 neuronal loss, and alterations in the expression pattern of several genes during the early epileptogenic phase were comparable to previous gene expression studies of the adult hippocampus of both experimental epileptic animals and patients with temporal lobe epilepsy (TLE). However, some changes seem to occur after SE specifically in the juvenile rat hippocampus. Insight of the SE-induced alterations in gene expression and their related pathways could give us hints for the development of new target-specific antiepileptic drugs that interfere with the progression of the disease in the juvenile age group

Fitting the Mechanical Refrigerator into the Home

Within the last five years the mechanical refrigerator has become a popular piece of household equipment. Its year-round use has caused architects and others interested in planning for the convenience of the housewife to recommend placing the new cabinet in kitchens and other convenient places, with little thought about the effect on the operation of the refrigerator. The purpose of this publication is to point out some of the conditions under which the refrigerator has been expected to operate successfully, and some of the effects of these conditions upon the operation of the machine

Scalable wavelet video coding using long-term memory motion-compensated prediction

Temporal redundancies are the key to high compression ratios in video coding. In order to improve the prediction gain of motion compensation the concept of long-term memory motion-compensated prediction has been developed. More frames than the previously decoded frame can be taken into account for motion compensation. Usually the motion is estimated in the encoder, where all unencoded frames are accessible. We investigate the applicability of long-term memory motion-compensated prediction to a scalable wavelet video coding scheme using backward motion compensation, where the motion is estimated in both, the encoder and the decoder

Optimized bit allocation for scalable wavelet video coding

The hybrid coding scheme is employed in all established coding standards. A forward motion vector field is estimated and applied for motion compensation. The remaining prediction error and the motion vectors are transmitted to the decoder. The discrete cosine transform is used for transform coding of the prediction error. The extension of this coding scheme to scalability is not easily achieved and the performance of standard video coders when using scalability options can often be reduced to the performance of simulcast coding

Fast full search block matching based on combined SAD and MSE measures

A new fast block matching algorithm is presented. The sum of absolute differences (SAD) and the mean square error (MSE) are used to find a suitable motion vector. A lower bound for both error measures is exploited to reduce the number of search positions and therefore the computational requirements. The error measures for the remaining search positions are calculated simultaneously so that the computational load for these calculations only slightly increases. The algorithm is compared to a fast full search block matching algorithm based on the same concept but only using the SAD or the MSE as the matching criterion. It is shown that the algorithm using both error measures combines the advantages of both algorithms using only the SAD or the MSE

Least-asymmetric signal extension for two-band paraunitary FIR filter banks

An algorithm for least-asymmetric signal extension for two-band paraunitary FIR filter banks is derived. The development of the algorithm is governed by the symmetric signal extension method for perfect reconstruction filter banks with even-length linear-phase filters. The approach yields an equality-constrained least-squares problem which is solved efficiently. The computational load is evaluated and simulation results for comparison of least-asymmetric and circular signal extension are presented

Fitting the Mechanical Refrigerator into the Home

Within the last five years the mechanical refrigerator has become a popular piece of household equipment. Its year-round use has caused architects and others interested in planning for the convenience of the housewife to recommend placing the new cabinet in kitchens and other convenient places, with little thought about the effect on the operation of the refrigerator. The purpose of this publication is to point out some of the conditions under which the refrigerator has been expected to operate successfully, and some of the effects of these conditions upon the operation of the machine